Measuring C02

[Branch]

Has anybody used the Hanna C02 test kit and had problems with their readings after the solutions have been opened? The kit, not a cheap item, appeared to work accurately at the outset in the summer but now I cannot get the test sample to turn pink no matter how active solution I put in. To check whether it was simply a case that my tank had too much C02 I tried the kit on pure RO water and it still didn't react? If the test kit is naff does anybody know of a more accurate means of testing for C02. Finally what would be the signs if too much C02 was present in the tank? B

[Filip]

Don't know about Hanna test kits , but I've measured my Co2 level with a "drop checker " . It measures the pH drop due to the Co2 addition and changes it's colour from blue (low Co2 )through green(moderate Co2 ) to yellow (high Co2 levels ) .
You can do the same with any pH metter or a pH test kit .
A drop of 1 pH degree due to Co2 addition , approximates 30 ppm Of Co2 (that's the highest range ). A PH drop of 0.5 approximates 15 PPM of Co2 and that would be the safe zone you should aim with discus in your tank.

Too much CO2 (above 30 PPM CO2 ) mess up with the abbility of fish to utillize oxigen and they start to breathe heavily and eventually suffocate .